Fluid-compressor.



J. S. BARNER.

FLUID COMPRESSOR. APPLICATION FILED MAR. 2. 1909.

1,171,017. Patented Feb. 8,1916.-

. 3 SHEETS-SHEET lj/EW 4 ATTORNEYS Tm. COLUMBIA PLANOORAPH co.WASHINGTON c.

I. S. BARNER.

FLUID COMPRESSOR.

APPLICATION FILED MAR-2.1909. 1,171,017.

Patented Feb. 8, 1916. W2

WITNESSES:

r/INV TOR m ATTORNEYS Tm: cvLuMmA ILANOGRAPII cuI. WASHINGTON, D. c.

J. S. BARNER.

FLUID COMPRESSOR.

APPLICATION FILED MAR. 2, I909.

1,171,017. Patented Feb. 8,1916.

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WITNESSES 53 INVENTOR B Y #UXM X W e ATTDRNEYS r l JOHN S. BARNER, OFALBANY, NEW YORK.

FLUID-COMPRESSOR.

Specification of Letters Patent.

Patented Feb. 8, 1916.

Application filed March 2, 1909. Serial No. 480,927.

To all whom it may concern:

Be it known that 1, JOHN S. BARNER, a citizen of the United States,residing at Albany, in the county of Albany and State of New York, haveinvented certain new and useful Improvements in Fluid-Compressors; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart, to which it appertains to make and use the same.

The object of the invention is to provide an improved air compressor andparticularly one of the compound type commonly employed in connectionwith air brake systems.

The particular nature of the invention will best be understood from aconsideration of the following description and the accompanyingdrawings.

In the drawings, Figure 1 is a central vertical section of the aircompressor, Fig. 2 is a plan on an enlarged scale with the main valvechest in section, Fig. 3 is a section on the line 33 of Fig. 2, Fig. 1is a detail illustrating the construction of the valve slide of Figs. 1,2 and 3, Figs. 5 and 6 are detail sections at right angles to oneanother of an improved valve construction, Fig. 7 is a vertical centralsection of an air compressor embodying certain improved featureshereinafter described, and Fig. 8 is a section like Fig. 3 showing themodified main valve in connection with the upper control valve.

The compressor comprises a high pressure steam cylinder 1 in which thehigh pressure piston 2 reciprocates, the piston 2 being connected by aconnecting rod 3 to the piston of the high pressure air cylinder 5;together with a low pressure steam cylinder 6 in which the low pressurepiston 7 reciprocates, the piston 7 being connected by piston rod 8 tothe piston 9 of the low pressure air cylinder 10. In the particularconstruction illustrated, the compressor is built up of a number ofcastings including, the bottom plate 11, illustrated in Fig. 1, servingas a head plate for the high and low pressure air cylinders andcontaining the inlet and discharge ports and passages for the lowpressure air cylinder; a casting 1 1 containing the cylinder chambers 10and 5 and the discharge ports and passages of the high pressurecylinder; a central casting 16 containing the upper inlet and dischargeports and passages of the low pressure cylinder, and

v ally also carrying the stuffing boxes for the piston rods and thecasing of the reversing tappet valve 17; the casting 18 containing thesteam cylinders (3 and 1 and the steam passages; an upper end plate 19forming the heads of the cylinders 6 and 1 and containing thecontinuation of the steam passages; and a valve chest 20 containing themain control valve which controls all of the steam passages of the highpressure and also of the low pressure cylinder, this valve chest beingentirely removable from the upper end plate for convenience of repair.

The foregoing description applies generto the form of compressorillustrated in Figs. 1, 2 and 3 and also to the form of compressorillustrated in Figs. 7 and 8; but it will be observed that thesecompressors differ specifically from one another in that the inletvalves 12 of the low pressure cylinder illustrated in Fig. 1 arereplaced by a series of inlet valves 18 controlling a series of inletpassages 49, in the construction illustrated in Fig. 7; and likewise thedischarge valves 13 of the low pressure cylinder, and the dischargevalves 15 of the high pressure cylinder, in Fig. 1, have been replacedby ball valves 58 and 59 of Fig. 7. Furthermore the main slide valve 21of Fig. 1 is replaced in Fig. 7 by a piston valve 51.

The mode of operation of the compressor of Fig. 1 will first bedescribed and then the nature of the modifications illustrated inconnection with Fig. 7 will be set forth. Referring then to thecompressor of Fig. 1, steam enters the main valve chamber 22, throughthe inlet pipe 23 from the boiler, between the pistons 24 and 25connected to the stem 26 which carries the slide valve 21. From the mainvalve chamber 22 the steam is free to pass by passage 27 (see Figs. 2and 3) into chamber 28 above the upper reversing tappet valve 22),holding it down and through by-pass 32 into chamber 33 to the left ofpiston Steam also passes from main valve chamber 22 by passage 35 intochamber 31 of reversing tappet valve 17 holding that valve up, andthrough bypass 36 and passage 30 into chamber 34: to the right of piston21, thereby balancing the main slide valve 21. It will be understoodthat in this position the piston 2 is just beginning its upward stroke,so that during the upward stroke the pressures on pistons 21 and 25 arebalanced and the slide valve 21 remains in the position illustrated,

downward stroke of to which it has already been brought in a mannerwhich will understood from the following description. At this time steamis admitted directly from main valve chamber 22 beneath the piston 2through passage 37, the exhaust steam above piston 2 passing throughpassage 39, recess d0 in slide valve 21 and passage ll to the lowpressure cylinder above piston 7, and the exhaust from the lowpressure'cylinder being through passage &2, recess in slide valve 21 andexhaust passageta to the exhaust pipe as (see Fig. 2). When thepistonreaches the upper end of its stroke the piston 2 strikes the stemof reversing tappet valve 29j'and lifts it, cutting off communicationwith the main valve chamber through by-pass 32 and opening a path fordischarge of the steam in chamber 33 through passage 32, the lowerportion ofthe tappet valve chamber below the piston, and'dischargeorifice 45 directly to the exhaustat atmospheric pressure. Thisdischarge of the pressure in chamber 33 destroys the balance of the mainvalve 21 and the pressure in chamber as throws the valve to the left,thereby putting passage 37 in communication with the lower end of thelow pressure cylinder 6 through recess 43 in the slide valve ant passage4:2. At the same time the upper portion of the low pressure cylinder 6is open to the discharge port through passage l-1, recess -l0, andpassage lt, and live steam is admitted directly above the piston 2fromva'lve chamber 22 through passage In this way'the stroke of both thehigh'and low pressure pistons is reversed and when piston 2 reaches thelower end of its StifOli'G it valve 17, closing communication betweenchamber 22 and chamber and discharging chamber 34 through dischargeorifice Hi to atmospheric pressure, whereupon the slide valve isreturned to the position shown and the pistons are again reversed andthe cycle of operations is repeated.

The operation of air compression, with the apparatus of Fig. 1, is asfollows: On the piston 9 resulting from the downward stroke of piston 7,air is forced from the low pressure air cylinder 10 through lower valve13 into the lower end of high pressure air cylinder 5, and at the sametime air at atmospheric pressure is drawn through the upper inlet valve12 above piston 9. By virtue of the fact that the high pressure aircylinder is smaller than the low pressure air cylinder, this results ina compression of the air to say about forty pounds, and this pressureaids in lifting piston i and piston 2, which are moving up ward. Theupward movement of piston 4., against the forty pounds pressure inchamher 5 further compresses the air in that chamber and forces itthrough upper discharge valve 15 into the air reservoir which depressestapp'et' may be connected to port 47 and uponreversal of the movement ofthe pistons the compression takes place in the opposite direction andthe high pressure cylinder 5 discharges through lower discharge valve15, as will be understood without any further description. It will beobserved that with this arrangement, and using live steam at 200 pounds,exhausting at fifty pounds and with a compression by the lowpressure airpiston of forty pounds, these figures being taken merely by way ofexample, there is acting to move piston 2 against the-air to becompressed the pressure-of the live steam, two hundred pounds, thepressure of the air coming from the low pressure cylinder, forty pounds,and against this, aside from the work of final compression, the pressureof the exhaust steam, namely fifty pounds, thereby giving a compressingforce of about i one hundred and ninety pounds when using live steam attwo hundred pounds. 7 l i By way of further improvement andsimplification of the device, and for the purpose of further attainingthe ficient service of the various parts for along time withoutreplacement, I may substitute for the main slide valve of Fig. l,particularly when the steam is supplied under higher pressure, a pistonvalve like that shown at 51in Fig. 7, in which the slide 21 between theend pistons 2 l and 25 is replaced by a series of pistons 52 which serveto change the relative connections of the ports in the valve seat. Inthis case the live steam is not admitted directly to the valve chest anddoes not exert its pressure upon the movable valve, valve. On thecontrary, to the connection 53 from the steam is piped which it passesby tween two adjacent pistons 52 on the piston valve stem, and it willact with equal oressure on both of these pistons so as not to disturbthe balance of the valve. In the position of the parts illustrated inFig. 7, which corresponds in general with the valve position illustratedin Fig. 1, the steam passes from passage 54 through passage 37beneath'the high pressure motor piston 2 to raise that piston, and thelow pressure steam above piston 2 passes through passage 39, between twopistons as shown, through passage 41 abovethe piston in motor cylinder6, and from the lower portion of cylinder 6 the steam passes throughpassage 42, between the pistons of the piston valve'as shown, andthrough passage 55 to exhaust pipe 56. At the endof the stroke of piston2 the tappet valve 29 is actuatedas in Fig. 1 to change the posi tion ofthe control valve and reverse the;

movement. In that case passage 54 is condesirable end of efas' 'in thecase of a slide of the piston valve 7 there is only steam above piston2; passage 37 is connected with passage 42 to lead the exhaust steamfrombelow piston 2 to the bottom of cylinder 6, and the upper portion ofcylinder 6 exhausts through passage 41 and passage 57 to exhaust pipe56. It will be observed that in this case the mode of operation of themain control valve in conjunction with the reversing tappet valves isthe same as in Fig. 1, but the main control valve is moved Withoutopposition and with very little wear, and with no possibility ofhammering.

I have found that in the operation of air compressors, considerabledifficulty is encountered with the operation of the valves, by reason ofthe fact that the ordinary type of valve is liable to become dirty andstick, break or leak, and to overcome this difliculty I prefer toemploy, in the place of the valves 13 and 15 of Fig. 1, the type ofvalves illustrated in Figs. 5, 6 and 7. That is I substitute for theselift valves 13 and 15 commonly used, ball valves 58 and 59. Ball valves,by reason of their movement on their seats, will always present a cleansurface of contact, and they tend to have a self-grinding effect on thevalve seat to keep it perfectly round and true, and for these reasonsalone the single ball valves might be employed to advantage, but it isimportant, particularly for the valves connected to the low pressureside of the compressor, to employ lighter valves than the commonly usedlift valves, or than a single ball valve. To this end I form each valveseat of the valves 58 and 59 with a plurality of passages each of whichis controlled by a separate small ball 58 and 59. Such valves areextremely light and practically indestructible, and are always tight,and it would be of advantage to employ them also in place of the lowpressure inlet valves 12. I have, however, devised a further improvedarrangement of the inlet passage to the low pressure cylinder, wherebyatmospheric pressure is almost instantaneously obtained on the suctionside of the piston. This arrangement is illustrated in Fig. 7 and ischaracterized by the fact that in addition to the inlet passagescommonly employed, one at each end of the cylinder, I employ one or moreintermediate inlet passages distributed along the length of the cylinderwall, and these passages admit air along the length of the cylinder towhichever side of the piston may at the moment be the suction side.These passages are illustrated at 49 in Fig. 7 and may conveniently becontrolled by individual small ball valves 48 as shown, these passagesbeing of sufficient extent to freely admit the air, and the ball valvesbeing extremly light. In operation the upper passage 49 will commence toadmit air as soon as the downward stroke of piston 7 begins, and as theintermediate passages 49 are passed by the piston in succession theywill aid in admitting air above the piston thereby giving quickequalization. On the return stroke the lower passage 49 acts initiallyas the admission passage, and as the piston rises the intermediatepassages 49 admit air to the lower side of the piston, which has becomethe suction side. I have illustrated four passages 49, the upper andlower passage and two intermediate passages, but it will be understoodthat the invention is in no way limited to that number.

What I claim is 1. In a compound fluid compressor, a high pressure motorcylinder, conduits for the motive fluid communicating with both ends ofsaid cylinder, a low pressure motor cylinder, conduits for the motivefluid communicating with both ends of the low pressure cylinder, a mainsupply pipe for the motive fluid, and an exhaust pipe, and a singlefluid-actuated control valve controlling all of said conduits and soarranged that in one position it connects the main supply pipe with thelower end of the high pressure cylinder, the upper end of the highpressure cylinder with the upper end of the low pressure cylinder, andthe lower end of the low pressure cylinder with the exhaust, and in theother position it connects the main supply pipe with the upper end ofthe high pressure cylinder, the lower end of the high pressure cylinderwith the lower end of the low pressure cylinder, and the upper end ofthe low pressure cylinder with the exhaust, conduits for supplying fluidto shift said control valve, and a tappet valve at each end of the highpressure cylinder in position to be actuated by the piston in itsextreme positions, said tappet valves controlling the last named fluidconduits, in combination with a piston in each of said cylinders.

2. In a fluid-compressor, a motor cylinder with admission and exhaustports and passages, a piston in said cylinder, a fluid actuatedcontrol-valve controlling said passages and having in ctmimunicationwith each side thereof a conduit for admitting fluid thereto and aconduit for discharging fluid therefrom directly to atmosphericpressure, and two tappet valves located at opposite ends of the cylinderin position to be actuated by the piston in its extreme positions andeach controlling the admission and discharge conduits of one side of thecontrol-valve.

3. In a fluid compressor, a motor cylinder with admission and exhaustports and passages, a piston in said cylinder, a valve chest having aseat to which the said passages lead, a valve on said seat comprising astem carrying end actuating pistons and intermediate separating pistonscoacting ith a se to ang h r lati 11- ne ctions of the passages When thevalve is shifted, said valve having in communication with its chz in beroutside of each. of the end pistons a conduit for admitting h to a d onfr' ie hersin fl i id. here ro and o ppet i 3 ma ted at opposite ends ofth cylinder in pqsiigion to be actuated by the piston in its extreme

